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Synonyms

irreversible

American  
[ir-i-vur-suh-buhl] / ˌɪr ɪˈvɜr sə bəl /

adjective

  1. not reversible; incapable of being changed.

    His refusal is irreversible.


irreversible British  
/ ˌɪrɪˈvɜːsəbəl /

adjective

  1. not able to be reversed

    the irreversible flow of time

  2. not able to be revoked or repealed; irrevocable

  3. chem physics capable of changing or producing a change in one direction only

    an irreversible reaction

  4. thermodynamics (of a change, process, etc) occurring through a number of intermediate states that are not all in thermodynamic equilibrium

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Etymology

Origin of irreversible

First recorded in 1620–30; ir- 2 + reversible

Explanation

If you can't undo something, it's irreversible. Time is always irreversible, as is the damage done to your skin by too much sun, so be sure to wear sunblock! While you see reverse inside of this word, you wouldn't use it to describe a car that can't go backwards. However, if the car was in an accident and cannot be fixed, you could say that the damage done to the car was pretty much irreversible, in other words the car is totaled.

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Vocabulary lists containing irreversible

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

And by the time the symptom surfaces, the damage is often irreversible.

From MarketWatch ● Oct. 13, 2026

They provide a fixed monthly check, rather than a lump sum that could lead to a single, irreversible bad financial decision.

From The Wall Street Journal ● Oct. 4, 2026

Instead, chromosome changes tend to move along a restricted set of irreversible pathways that the researchers describe as "evolutionary highways."

From Science Daily ● Aug. 25, 2026

The National Trust for Historic Preservation, a preservation group, has led the lawsuit against the ballroom, arguing it is causing irreversible damage to a historical landmark.

From BBC ● Aug. 21, 2026

In reality, Ebola had not yet made a decisive, irreversible breakthrough into the human race,, but it seemed close to doing that.

From "The Hot Zone" by Richard Preston

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